In subsurface fluid distribution systems, such as water mains and supply pipes for fire control systems, it is often necessary to place manually operable control valves in locations that are remote from a manual access point. In other words, the valves often are buried below ground level or otherwise remotely located. In commercial buildings or other structures, the valve may be located below a concrete floor which is considered below "ground level" for purposes of this invention.
A typical fluid control valve, such as butterfly valves or the like, includes a rotatable valve member in the fluid line, with a valve stem projecting upwardly from the line. A valve actuator is fixed to the valve stem and often comprises a polygonal nut which is engageable by an appropriate wrench-like tool for rotating the valve. With buried valves, the wrench has an elongated shaft which terminates in a handle above ground level for rotating the subsurface valve.
It is highly desirable to provide some form of lockout or anti-tampering device for preventing unauthorized use of such buried valves. Unfortunately, most anti-tampering devices for valve stems have been designed for above ground applications because of the prevalence of tampering with such valves, such as common fire hydrants. There are few lockout or anti-tampering devices which are applicable for subsurface applications and those devices are relatively complicated and expensive.
There is a definite need for a simple lockout device for subsurface applications, and the present invention is directed to satisfying that need.